Daniel Sepec

The violin and keyboard sonatas of C.P.E. Bach are not very well known or recorded, which is a shame because when I first heard this music it was a revelation – I was astonished by their inventiveness. He was writing during a time of stylistic change, and these pieces are a door that opens to the world of early Haydn and Mozart, but they are also a missing link between the Baroque and Classical periods because Carl Philipp was writing in a Baroque style while combining new elements in the Classical language.

As a composer Carl Philipp was extremely productive and very diverse. Structurally his sonatas fit the Classical model, but within that structure he can be unusual, and you can suddenly lose your orientation.

 You don’t always know when to breathe, sometimes the pieces are longer than you expect, or there prise is not where you thought it would be, or is in a strange key. He had a unique way of writing, which is a bit rough and stubborn sometimes and at other times very modern, so his music sounds fresh to our ears. His approach is in the empfindsamer Stil (‘sensitive style’) – it is remarkably emotional, and these emotions often change quickly.

Unlike much Baroque music, which can be quite official-sounding, his music can be soft, describing an inner world. He was much more a keyboardist than a violinist – his father wrote music that was more violinistic – so playing this music is a challenge, although no more so than with Beethoven or Schubert where the music is often not especially well written for the violin.

For the modern player it is not simply a matter of playing the notes; you have to know how to play the many ornaments and understand the historical style. The ornaments tend to be easier to realise on the keyboard than on the violin, and it is important to play them naturally, with good expression and with equal interest in the keyboard part.

In some of his harpsichord sonatas Carl Philipp writes in the repetitions his own ornaments, and you can hear his authentic voice. We decided this was the most authentic way to approach the cadenzas – not to copy him, but to see how he would have done them and the tools he used. It is not really possible for two people to play a cadenza by improvising, so we had to make a road-map.

By playing this music a lot you enter into the spirit of it, and the ornaments and cadenzas become easier.We made the recording in Mülheim,in a church with a wooden roof and a wonderful acoustic. It was during the2014 World Cup, and when Germany won there was a lot of noise outside which made it difficult to find silent moments.

We had to resort to early mornings and late-night sessions, so the entire session took twelve days.The instrument I used for the recording is my own violin by Johann Friedrich Lorenz from 1792, and I used a late Baroque bow by Ralph Ashmead from the 1990s. The strings are by Damian Dlugolecki. Sometimes I use a gut D string wound with metal, but for this recording I used pure gut, which has a very special and characterful sound.I also used a wooden mute, which makes the violin much quieter.

Christine Schornsheim

The idea to record the complete sonatas for violin and keyboard only emerged during the project. We wanted to show the development from the first very simple sonatas to the extremely complicated Fantasia Wq80, and the huge variety of small nuances. C.P.E. Bach’s oeuvre gets progressively more expressive: the early sonatas, such as Wq71 or 72, are simple in structure and the movements shorter. They are not easy to play but Carl Philipp doesn’t overload them with ideas.

Then his sonatas get longer – he likes to repeat his ideas, so one sonata might last for 20 minutes. That is my only criticism of his music: at times he goes a little overboard. The Fantasia Wq80 was originally written for keyboard – the violin part was added later. It is a late piece, with the beautiful title ‘C.P.E. Bach’s sentiments’. It is the most inventive work in this collection and is very rich in effects. If the music truly represents his feelings, the Fantasia would be a key to how he thought and composed.

It is a torn piece, with outbursts of emotion and extreme contrasts ranging from grief and desperation to rage, anger, even madness – though it ends with a cheerful Allegro. The entire palette of emotions and expressions is contained in this piece. C.P.E. Bach’s music is uncomfortable in that you really have to tap into it and develop it.

Sometimes the notation is sparse, so you have to think of ways to fill it and decide on expressions to furnish every detail. For our recording we experimented and improvised a lot. You have to analyse what you find in his other works: for example, he had favourite ornamentations, such as a conjunct double appoggiatura or a combination of a trill and a turn, and he loved to extend ornaments, even in the smallest of spaces such as a semiquaver.

Modification can also mean changing the dynamics, even adding pauses – the important thing is to create surprises. For the early sonatas I used a harpsichord instead of a clavichord, which is too soft next to a violin.

And because a fortepiano from C.P.E. Bach’s period would have been impossible to find, I used a tangent piano for the later works, which will divide opinion because there is no evidence that C.P.E. Bach saw or played such an instrument. But I think if he had encountered it he would have written for it, because the tangent piano has such a variety of colours and suits his ideas and music perfectly.